A similar method and a similar x-ray examination unit are generally known, where the attenuation values established are displayed directly as gray values in a projection representation in connection with the known method and the known x-ray examination unit. X-ray units and x-ray methods of this type are mostly used for the purposes of medical imaging where the radiation parameters, such as the tube voltage, tube current and exposure time, and where relevant also a prefiltering stage, are adapted to the current imaging problem. In this respect, the energy spectrum used for the x-ray radiation has a strong effect on the projection depiction generated since different absorption coefficients occur for the same radiographed material as a function of the energy spectrum of the x-ray radiation utilized. Thus, for example, the representation of vessels dyed with contrast medium requires a lower tube voltage than that of soft tissue differences. While low tube voltages can be used in the case of thin patients, the tube voltage has to be increased in the case of thick patients in order to increase the radiation transparency on the one hand and utilize the higher efficiency of the x-ray tube at higher voltages on the other. However, this forced increase in voltage has an adverse effect on the contrast in the image due to the increased transparency and the growing scattered radiation component. These losses in contrast are currently either accepted or an attempt is made to compensate for this drawback with the aid of tightly configured gray value windowing. Great experience is nevertheless necessary for the purposes of assessing such projection x-ray photographs in order to be able to compensate for the differences in the creation of the x-ray photographs in the right way for a correct finding.